Hydraulic broaching machine



Nov. l1, 1930.

F. J. LAPOINTE HYDRAULLG BRQACHING MACHINE 5 Sheets-Sheet l Filed Oct. 7, 1927 Nov. 1l, 1930. F, J, LAPQlN'l-E 1,781,114:

HYDRAULIC BROACHINGIMACHINE 1 Filed oet. fr 1927 5 sheets-sheet` 2 61 :fi i5 o o o E 13 l2' o` 63 62 65 "0 1E e a l, Y K L- 11 11 lo' l lvenlor:

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Nov. 1 1, 1930.

F. J. LAPOINTE HYDRAULIC BROACHING MACHINE Filed Oct. '7, 1927 Rg. a.

5 sheets-'sheet 5 NOV- ll, 1930 F. J. LAPolNTE HYDRAULIC BROACHING MACHINE l Filed oct'. 7, 1927' 5 sheets-shet- 4 lwenlr:

llapoel'c, v E3 m@ NOV- 11, 1930 F. J. LAPolNTE 4 1,781,114

' HYDRAULIC BRoAcHING MACHINE l Filed oct. 7,A 192'? 5 sheets-sheet` 5 lwenor: lanclls' llapoinle,

Jiffy Patented Nov. 11,1930

FRANCIS J. LAPAOINTE, F .ANN ABBO, MIHIGAN HYDRAULIC BBOACHING Application led October 7, 1927. Serial No. 224,632.

This invention relates to breaching machines and particularly to machines of this 'character which are of a pull type and actu-V ated byhydraulic means, the obj ect of the invention being the production of a machine of this class which will be semi-automatic dispensing with the handling of the broach by' the operator during the broachingoperation. lThis object is attainedby the mechanism illustrated in the accompanying drawing.'

'Y For the purpose of illustrating the invention, one preferred form thereof is illustrated inthe drawings, this form having been found to give satisfactory and'reliable results, al

though it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized, ,and the invention is not limited to the precise arrangement and organization of these instru- 2o mentalities as herein shown and described 'eX-l cept as required by the scope of the appended claims. A

Of the drawings: Figure 1 represents a front elevation of a broaching machine embodying the principles of the present invention. Figure -2 represents a rear elevation of the same.

Figure 3 represents an elevation of the right side of same.

Figure 4 represents an elevation of the left side of sa-me.

Figure 5 represents a vertical section of the upper cylinder, its ram, the tool 'pping members `and the means for contro ling theing in elevation the tool gripping devices, and

Figure 9 re resents a section ofthe main controlling va ve. 1

Similar characters indicate like .throughout the several figures of the 1 Y the drawings 10 is a base provided with arts ears 11 by which it may be secured to the floor by means of bolts 12. y

The base 10 has upwardly extendin side walls 13 forming a receptacle to catc the waste oil and chlps removed from the work during the breaching operation. v

Centrally disposed on-the base 10 is acasing 14 having an opening in its front side the lower part of .which is normally closed by a c splash plate 15 which may be removed when 60 it is desired to gain access to the interior of said casing.

Within the casing 14 is a vertical cylinder 16 having a plunger 17 therein, said cylinder having an oil pipe 18 communicating with the 05 interior thereof beneath the plunger 17.

When oil is admitted from the pipe 18 be- 'i neath said plunger 17 it will be moved up-4 wardly. i

The upper end of the plunger 17 is provided 70 with a socket 19 to receive the lower end of a broaching tool 20.

This socket 19 is provided with a soft metal bushing 21 and has a soft metal disk 22 in the bottom thereof, the disk 22 and bushing 21 75 being provided to prevent injury to the breaching tool.

A liange 23 extends from the lunger and from the opposite sides of this ange 23 extend springs 24, the opposite ends of which are secured to the ange 25 at the lower end of the cylinder 16.

- These springs 24 serve -to return4 the plunger I7 to its'lowest position when the fiow of oil/is cut olf from the pipe 18,.

Within the casing 14 is a work support` ing table 26, the upper face of which is inclined towards an openingv14* in .one side wall of the casing 14,' this side wall having secured thereto beneath said opening a delive 'chute 27. y.

en the breaching operation is completedihe work will slide down the inclined face of .the table 26 onto'the chute 27 to be delivered intoany suitable receptacle.

In front of the table 126 is a shelf 26* on which may be placed the work tobe operated upon.

The table 26 has a soft `metal bushinlS extending therethrough and surroun g 10o the breaching tool 20, the upper end of which in its lowest position extends a short 4distance above t-he inclined upper face of through which extends the usual work bushing 29 against which the Work contacts during the broaching operation'.

To the top of the casing 14 is secured the framework 30, the upper end of which has formed integral therewith a cylinder 31 which is alined with the cylinder `16.

In this cylinder 31 is a ram 32 having a reduced portion 33 extending downwardly through a stuffing box 34 in the lower end of the cylinder.

To the lowerwend of the reduced'portion 33 of the ram'm32 is secured a block 34"- through which extend two parallel oscillating pins 35, 35x each having a gear segment 36 secured thereto, these gear segments meshing so that when one pin 35x is oscillated in one direction the other .pin 35 will be oscillated in the opposite dire'ction.

The pin 35x has an actuating arm 37 secured thereto andv each pin 35, -35x Vhas a gripping 'jaw 38 secured thereto.

The jaws 38 are inclined upwardlytoward each other and are normall retained in this osition by the weight of t e arm 37.

The breaching tool 20 has a shouldered groove 39 near its upper end and when said tool is raised by the plunger 17 the jaws 38 `will enter said groove 39 and'if the ram 32 is then moved upwardly the broaching tool 2O will be drawn up t-hereby lifting the work therewith until said work comes in contact with the bushing 29 which prevents further upward move-ment of the work.

As the ram 32 continues its upward movement the tool 20'will be pulled through the work and complete the broaching operation.

As the lower end of the tool leaves the work, the latter will drop onto the table 26 and slide down the inclined facethereofto the delivery chute' 27 and requires no handling by the operator? l l Projecting upwardly from the top of casing 14 is a standard 40 having pivoted the-reto 'a latch 41 in the path of the arm 37.

When the ram 32 moves upwardly the arm 37 will come in contact with the latch 41 and move it about its pivot so that said arm 37 may pass, but when the ram moves downwardly, the arm 37 will come in contact with the latch 41 and as ythe latch 41 cannot move downwardly about its pivot, the arm 37 must move about the axis of pin 35 andoscillate said pin.

This movement of the pin 35* will be transmitted to the pin 35 through the segments 36, thereby causing the gripping jaws to the' lower ends of which are secured to the side walls 13 of the base 10.

These springs 44 pull down the' ram 32 when the oil pressure is removed from beneath said ram.

The bar 42 has a rod 45 secured thereto and extending upwardly therefrom through an ear 46 projecting forwardly from the upper end of the c linder 31.

The upperl end o the rod -45 has a collar 47 secured thereto between which and the. ear 46 is a spring 48 which prevents any jar when the ram 32 reaches vits lowest position. I

The rod 45 also has adjustably secured thereon a stop collar 49 which in the upward movement of the ram 32 comes into contact .with thevlever 50 and moves it about its pivot 57 to cut 0H the supply of oil to cyl-v inder 31.

This lever 50 has a end by which it may be operated manually 1f desired. g

, The lever 50 has pivotally connected. theretothe upper end of a rod 53, the lower end of which is articulated to the treadle 54 which is depressed when it is desired to admit oil to the bottom of cylinder 31.

The cylinder 31 is provided with a direct reading gauge 55 indicating total tonnage and number of pounds exerted.

To the ri ht of the treadle 54 is another treadle 5 6 wgh of cylinder 16.

handle 52 atiits outer` ich is depressed when it is desired to admit oil from pipe 18 to the interior The lever 50'is secured to the oscillatingl shaft .57 mounted `in bearings on the framework 30, the opposite end said rod having.

another lever 58 secured thereto and movable therewith.

' From the right. side of the lcasing 10 exy ten ds a barrel 59 through which extendl downwardly two rods 60, the lower ends of which are attached to springs 61 connected at their lower ends to the treadles 54, 56 and serve to retain these treadles in raised position under normal conditions.

The treadle 56 is secured to an oscillating shaft 62 mounted in brackets 63 at the rear of the base 10 and the treadle 54 is loosely mounted on said shaft 62 between the treadle and a motor 67, the latter driving said pump by means of its driving shaft 68 connected by any suitable coupling to the shaft 68* of the pump 66. v

To the rear of the frame work 30 are mounted brackets 69 supporting an oil reservoir 70 which is connected by the pipe 71 to the inlet of the pump 66 which pump is of the twin screw type and non-pulsating.

As this particular form of pump is no part of the present invention it is deemed unnecessary to illustrate or describe the same in detai From the outlet of the pump extends a pipe 72 which leads through a valve 73 to the nterior of the cylinder 31.

When the pump 66 is in operation and the valve 73 is closed, oil will be admitted to the cylinder 31 beneath the ram 32 and cause the latter to be raised.

When the valve 73 is open and in communication with the pipe 74 the oil from the pump 66 may pass again into the reservoir 7 0 and make a complete circuit.

Secured to the framework 30 is an arm 75 having a bifurcated member 76 adjustably mounted in its upper end.-

The valve 73 has a reciprocating plunger 77 therein and between the outer end of this plunger 77 and the bifurcated member 76 are two toggle links 78, connected together and' to a link 79 by a pivot pin 80.

The upper end of the link'7 9 is pivotally connected to the free end of the lever 58 at the rear end of shaft 57.

By depressing the treadle 54 the. levers 50, 58 are moved downwardly causing the toggle links 78 to straighten and move the plunger 77 to close the oil passage to the pipe 74, the pivot 8O being slightly below the axis of the plunger 77.

The toggle mechanism remains straightened and oil continues to enter the cylinder 31 until the collar 49 contacts with the lever 50 and raises it into the position indicated in Fig. 1, this raising of lever 50 being transmitted to the lever 58 and causing the toggle lmks to be moved into the position indicated Ain Fig. 2, thereby moving the plunger '77 the reservoir through the pump 66 and back to the reservoir 70.

During this circulation of oil the lower end of the cylinder is in communication with the pipes 72, 74 and-the oil is free to enter the` cylinder 31 beneath. the ram 32, but as there is no pressure at this time there is no effect upon the ram and it is not raised.

When the plunger 77 is forced to its seat 81 closing the entrance to pipe 74 the oil from pipe 72 will pass through the annular groove' 82 to the cylinder 31 and as the oil at this time is under pressure it necessarilyv causes the ram 32 to move upwardly in said cylinder until the plunger 77 isagain moved'from its seat 81.

When the plunger 77 is removed'from its seat 81 the oil in theo linder 31 beneath the ram 32 is free to pass t erefrom into the pipe 74 and back to the reservoir 70.

From the upper end of the cylinder 31 extends a pipe 83 vwhich leads to the reservoir 70, and takes care of any oil which may leak 'bly the ram 32 and any air which may be in t e youtwardly so that there is always a pressure which will hold the plunger 77 firmly to its seat 81 whenv the toggle is straightened.

In the pipe line 72 is a relief valve 84 from which extends a. pipe 85 communicating with the overflow pipe 83.

When there is too much pressure of oil in pipe 72 the relief valve 8 4 will operate rto uncover the entranceto pipe 85 and thereby permit the excessive amount of oil in pipe 72 to return' to the reservoir.

The motor shaft 68 has mounted thereon a sprocket Wheel 86 which imparts rotary movement to the shafts 87, 87 x of two smaller pumps 88, 89 similar to the pump v66, said shaft 87x-having a sprocket wheel 88 thereon connected to sprocket wheel 86 by an endless chain 90.

The-shafts 87 87x are coupled together in any well known manner.

The pump 88 has an inlet pipe 91 leading thereto the lower end of whichv is in the receptacle formed in the base 10 and this lower end is provided with a strainer 9 2.

The pressure side of said pump 88 has a lpipe 93 leading therefrom to a T 94, one

branch of which has a pipe 95 extending therefrom, the open end of which is adapted to discharge oilv on the broaching tool 20 preparatory to its broaching operation.

This pipe 95 has a valve 96 therein by f which the amount of oil may be regulated or it may be closed entirely in cases where it is unnecessary to oil the tool.

Another branch of the T 94 is connected by a pipe 97 to a relief valve 98 having extending downwardly therefrom a pipe 99,

the lower end of which extends into the recepta'cle of base 10.

When the pump 88 is operating oil will be drawn continuously from the receptacle in the base and returned thereto whether the valve 96 is open or not.

When the valve 96 is open in order to splash oil Aonto the broaching tool the relief valve 98 may be adjusted by means of the head 100, so that a sufficientv pressure of oil will be created in the discharge pipe 95.

The pump 89 has its inlet connected to the leading. therefrom toa relief valve 104 from which extends a pipe 105 connecting with a.

pipe 106 leading to the reservoir 70.

When thereis an excessive pressure in the pipe 103 the relief valve 104 will operate to permit the excessive amount of oil to return to said reservoir. i

The pipe 103 has a branch pipe 107 leading therefrom to a valve 108, the lower end of which has a seat therein for the end of the plunger 109.

The lower end of this valve 108 communicates with the pipe 106 leading to the reservoir 70.

' The plunger 109 of the valve 108 iscon'- nected by link 110 to the lever 111 pivoted to the casing 14 and having its outer free end connected by a rod 112 to the outer treadle 56. The valve 108 is similar in construction to l the valve 73 previously described and the side outlet from the valve is connected by the pipe 18 with the lower end of the cylinder 16.

When the treadle 56 is depressed the plunger 109 will be forced toits seat closing the pipe 106 and then the oil under pressure will enter cylinder 16 beneath its plunger 17 l andforce it upwardly.

The lower end of the plunger 17 is rovided with a downward projection 113 o reduced diameter so 'that tlie discharge end of the pipe 18 can never be closed by said plunger 17 when in' its lowest position.

Projecting from the right side wall 134 of base 10 is a boss 114 through which extend adjustable lstop members 115, 116 to limit the upward movement of the treadles 54, 56 respectively.

After the work has been placed around the broaching tool and resting on the table all further handling of the work by the operator is unnecessary.

As the raising of the tool 20 into position to be seized Yby the jaws 38 and the pulling of the tool 20 through the work is wholly effected by foot pedals or treadles it is obvious that the o rater has both hands free at all times to p ace the work upon the work table and thus materially assists in the rapid operation ofthe machine.

When the work has been dropped over the shank of the broach 20 the operator depresses the treadle 56 until the broach has been lifted and seized by the jaws 38. l

He then turns his'. foot slightly onto the treadle 54 and depresses it.

As soon aspressure has been removed from the treadle 56 the plunger 17 will be returned automatically to its lowest position.v

As soon as the treadle 54 has been depressed the broach 20 will be pulled through the work and when the broach is disconnected from the work the latter will be discharged from I the machine without handling.

. When the collar 49 actuates the levers 50,v y

-58 the ram 32 will start-on its downward stop as its end strikes the soft metal disk 22 will release all chips therefrom, this being due to the sudden shock and also to the continuous stream of lubricating oilbeing layed upon the broach beneath the angular ta le 26.

It will be noted that the broach is never4 handled by the operator during the successive v broachipg operations.

The pump 88 supplies a cutting lubricant to the broach 20 during the operation ofthe machine and this lubricant is collected in the receptacle of. base 10, strained, and usedl over and over again. f

While this lubricating oil is played upon the broach 20 it is prevented from splashing the operator by means of the splash plate 15.

It is believed that the operation and many advantages of the invention will be understood without further description.

Having y thus ldescribed my invention, I claim- -1. In` a breaching machine, two alined hydraulic cylinders one above the other; a ram reciprocable in the upper cylinder; a

plunger reciprocable in the lower cylinder rovided with a broach receiving socket in its upper end; a work support provided with a vertical opening through which the broach extends; a treadle actuated `mechanism for admitting oill to the lower cylinder beneath said lunger; means on the lower end of the ram or automatically seizing the upper end of the broach when said broach has been raised by said plun er; and treadle actuated mechanism for admltting oil to the upper cylinder to raise the ram when said broach has been gripped by said seizing means. j

2. In a. breaching` machine, two alined hydraulic cylinders one above the other; a rain reciprocable in the upper cylinder; a plunger reciprocable in the lower cylinder provided with a broach receiving socket in its upper end; a work support provided with a verticalopening through which the broachv extends; a treadleactuated mechanism for admitting oil to the lower cylinder beneath said plunger; means on the lower end of the ram for automatically seizing the upper end of the broach when said broach has been raised .by said plunger; treadle actuated mechanism for admitting oil. to the upper cylinder to raise the ram when said broach has been gripped. by said seizing means; and

automatic means for returning said ram to its lowest position.

3. In a broaching machine, two separated alined hydraulic cylinders one above the other; a ram reciprocable in the upper cylinder; a plunger reciprocable kin the lower cylinder provided with, a broach receiving socket in its upper end; gripping jaws on the lower end of the-ram for seizing the broach preparatory to pulling it through the work; a work support between said cylinders having a guide for the upper end of the broach; means for admitting fluid to the lower cylinder and raising the plunger and broach supportedl thereby into position to permit the jaws vvto grip the broach; and means for subsequently admitting' fluid to the upper cylinder and raising said ram and the gripping jaws thereon.

4. In a broaching machine, two alined hydraulic cylinders one above the other; a ram reciprocable in the upper cylinder; a plunger reciprocable in the lower cylinder provided with a broach receiving socket in its upper end; gripping-jaws pivoted to the lower end of the ram for seizing the broach preparatory to pulling it through the work; means, for admitting fluid to the lower cylinder and raising the plunger and broach supportedV thereby into positionl to permit the jaws to grip the broach; means for subsequently admitting fluid to the upper cylinder and raising said ram and the gripping jaws thereon; and means wherebysaid jaws may be moved` simultaneously about their pivotscomprising an arm extending from the pivot of one of said jaws and a latch coacting with said arm on the downward movement of the ram to release said aws from the broach.

5. In a broaching machine, a vertical casing having at the top thereof a horizontal top plate provided with a broach receiving opening and adapted to sustain the strain upon the work during the broachingoperation; a fixed immovable work-supporting table within said casing belowl said plate having an elongated tubular guide therein through which the broach normally extends; means below said table alined with said guide for projecting the broach upwardly with its upper end extending through the top plate opening; reciprocating means above the top plate and alined with saidk guide fo-r automatically seizing the-upper end of the broach vand pulling said broach through the work,

said means consisting in part of two ,oppositely disposed pivoted jaws; and means for retaining said reciprocating means at rest during the operation of said broach projecting means.

6. In a broaching machine, a casing having at the top thereof a horizontal .top plate provided with a broach receiving opening and adapted to sustain the strain upon the work during the broaching operation; a fixed immovable work-supporting table within said casing vbelow said plate having alined with said opening a tubular guide therein through which the broach normally extends; ahydraulic plunger below said table and alined with said guide for projecting the broach upwardly with its upper end extending through the top plate opening; reciprocating means above the top plate for automatically seizing the upper end of the 'broach and pulling said broach through the work; and means for retaining said reciprocating means at rest during the operation of said broach projectmg means. Y

7. In a broaching machine,- a casing having at the top thereof a horizontal top plate provided with a broach receiving opening and adapted to sustain the strain upon the work during the broaching operation; a fixed immovable work-supporting table within said casing below said plate having a tubular guide therein through which the broach normally extends; means `below said table and alined withy said tubular guide for project-- ing the broach upwardly with its upper end extending through the top plate opening; a hydraulic rain above the top plate alined with said guide and provided at its lowest end with means for automatically seizing the up.- per end of the broach; means for retaining said ram at rest during the operation of said projecting means; and means for raising the ram when said broach has been engaged by said seizing means.

8. In a broaching machine, 4a framework provided with a horizontal fixed plate hav'- ing a broach receiving opening and adapted to sustain the strain upon the work during the broaching operation; a fixed immovable table beneath said plate having in alinement with said opening a tubular guide through which the broach normally extends; h draulic means below the table for lifting a roach and projecting itsupper end through said opening; hydraulic mechanism above said plate provided at its lowest end with means for automatically gripping the projected end of said broach, said hydraulic mechanism being adapted to remain at rest during the operation of said broach projecting mechanism; and means for actuating said hydraulic mechanism subsequently to pull the gripped broach through the work.

9. In a broachlng machine, a horizontal fixed plate lhaving a'broachreceiving opening and adapted to sustain the strain upon the work during the broaching operation; an

immovable work-supporting table below said plate having an elongated guide for thefupper end of abroach; a cylinder above 'said plate alined with'said op ning; a ram 4in said cylinder; means movable. with said ram for gripping the end of a broach projected through said opening; means for producing hydraulic pressure in said cylinder beneath fixedplate having a broach receiving opening and adapted to sustain the strain upon the work during the breaching operation; a cylinder above said plate alined with said opening; an immovable work-supporting table below said plate having anv elongated guide for the upper end of a broach; a ram in said cylinder; means movable with said ram for gripping the end of a broach proliected through said opening; means for producing hydraulic pressure in said cylinder beneath the ram and raising said ram after4 the broach has been seized; means operative after an upward movement of said ram for shutting od the pressure; automatic means tor subsequently lowering the ram; means operable during the lowering of the ram for' automaticallyv actuating `the gripping means and releasing the breach thereby permitting it to fall by gravity; a reciprocating member beneath said table provided with a socket to receive the lower end of the breach at the end of its fall and retain it in verticalY position; and means for raising said reciproeating member to elevate said broach into position to be seized by said gripping means while the ram is at rest.

11. In a breaching machine, a plunger adapted to supporta broach in vertical position; hydraulic means for raising said plunger; a work-supporting table above said plunger having an elongated guide for the upper end of the breach supported by said plunger; a cylinder alined with and above said plunger; a horizontal plate below said cylinder adapted to sustain the strain upon the work during the broaching operation; a reciprocating ram in said cylinder normally at rest in its lowest position; means movable with said ram for automatically gripping the broach; a continuously actuated pump; a pipe 'from the pressure side of said pump communicating with and adapted to admit fluid to said cylinder beneath said ram after the breach has been seized by said gripping means; means permitting the escape of the fluid from said cylinder at the end of the upward movement of said ram; and means for lowering the ram when said fluid escapes from sald cylinder.

12. Ina breaching machine, a plunger adapted to support a breach in vertical pesition; hydraulic means for raising said gripping the broach; a continuously actuated 7.t

pump; a pipe from the pressure side of said pump communicating with and adapted to admit fluid to said cylinder beneath said ram when the breach has been seized; an oil reservoir; a pipe therefrom to the inlet of said pump; a valve in the pipe from the pump to said cylinder; a lreturn pipe from said valve to said reservoir; and a valve plunger in ,said

vvalve adapted to close the mouth of said .return pipe t0 build up an oil pressure within said cylinder., l

13. In a broaching machine, a plunger adapted to support a breach in vertical position; hydraulic means for raising said plunger; an immovable work-supporting table above said plunger having an lelongated guide for the upper end of the breach supported by said plunger; a cylinder alined with and above said plunger; a horizontal plate below said cylinder adapted to sustain the strain vupon the work during the breaching operation; a reciprocating ram in said'cylinder; means movable with said ram for automatically gripping the breach consisting of two oppositely disposed jaws; a continuously actuated pump; a pipe from the pressure side of said pump communicating with and adapted to admit fluid to said cylinder'vbeneath said ram when the broach has been seized by the gripping means; an oil reservoir; a pipe Vy plunger; and a treadle for straightening the toggle mechanism and forcing the valve plunger to its seat.

14. In a breaching machine, a plunger adapted to support a breach in vertical posltion; hydraulic means yfor raising said pluri er; an immovable worksupporting table a ove saidplunger having an elongated r1 guide for the upper end of the breach supported b said plunger; a cylinder alined with an above said plunger; a horizontal plate below said cylinder adapted to sustain the strain upon the work during the bnoach- 1.1

ing operation; a reciprocating ram in said cylinder; means movable with said ram for c automatically gripping the broach; a continuously actuated pump; a pipe ffrom the pressure side of said pump communicating. with 1 I and adapted to admit Huid to said cylinder beneath said ram after the broach has been seized by the 4gripping means; an oil reservoir; a pipe therefrom tothe inlet of said pump; a valve in the pipeto said cylinder; a return pipe from said' valve to said reservoir; a valve plunger in said valve adapted to close the mouth of said return pipe to build up an oil pressure within said cylinder; toggle mechanism for actuating said valve plunger; a treadle for straightening the toggle mechanism and forcing the valve plunger te its seat; and means operable by the upward movement of the ram for breaking the toggle and eecting communication between the cylinder and said return pipe.

15. In a breaching machine, a plunger adapt-ed to support a broach in vertical position; hydraulic means for raising said plun er; an immovable work-supporting table a ove said plunger having an elongated guide for the upper end of the broach supported byl said plunger; a cylinder alined With and above said plunger; a horizontal plate below said cylinder adapted to sustain the strain upon the Work during the broaching operation; a reciprocating ram in said cylinder; means movable with said ram for reservoir; a pipe therefrom to the inlet of said pump; a valve in the pipe. from lsaid pump to said cylinder; a return pipe fromsaid valve to said reservoir; anda valve plun er in said valve adapted to close the mout of said return pipe to build up an oil pressurewithin said cylinder, said valve plunger havingan annular peripheral groove always in communication with the cylinder and the oil supply pipe leading thereto.

16. In a breaching machine, a cylinder; a plunger therein adapted to support a broach inl vertical position; an immovable work-supporting table above said plunger having an elongated guide for the upper, end of the broach supported by said plunger; another cylinder above the plunger cylinder; a reciprocating ram therein alined with and above said plunger; a horizontal plate below said ram cylinder adapted to sustain the strain upon the work during the broaching operation; means movable with said ram for automatically gripping the broach, said grip- 'ping`means consisting of two oppositely disvreciprocable in the elongated guide for the upper end of the' broach supported by said plunger; another cylinder above the plunger cylinder; a reciprocating ram therein alined with and above vsaid plunger; a horizontal plate below said ram cylinder adapted to sustain the strain upon the work during the broaching operation; means movable with said ram for automatically gripping the broach, said gripping means consisting of two-oppositely disposed pivoted jaws; a continuously actuated pump;

a pipe from the pressure sideof said pump communicating with and adapted to admit iluid to said plunger cylinder beneath said broach-.supporting plunger; an oil reservoir; a pipe therefrom to the inlet of said pump; a valve in' thepipe from the pump to said cylinder; a return pipe from said valve to said reservoir; and a valve plunger adapted t close the mouth of said return pipe to build upan oil pressure within said cylinder.

18. In a broaching machine, a cylinder; a plunger therein adapted to support a broach in vertical position; an immovable work-supporting table above said plunger having an elongated guide fory the upper endof the broach supported by said plunger; another cylinder above the plunger cylinder; a reciprocating ram thereinalined vwith and above said plunger; a horizontal plate below said cylinder adapted to sustain the strain upon the work during the broachin operation; means movable with said ram or auto- Y matically gripping the broach; a continuously actuated pump; a pipe'from the pressure side of said pump communicating with and adapted to admit iuid to said plunger cylinder beneath said broach-supporting plunger after the broach has been seized by the gripping means; a pipe therefrom to the inlet of said pump; a valve in said pipe to said cylinder; afreturnpipe from said valve to said reservoir; a valveplunger adapted to close the mouth of said return pipe to build y up an oil pressure withinsaid cylinder; and a treadle actuated mechanism for forcing said valve lunger to its seat.

19. draulic cylinders one above the other; a ram reciprocable in the u per cylinder; a plunger lbwer cylinder provided with a broach-receiving socket in its upper end; means for admitting oil to the lower cylinder beneath said lunger; means on the lower end of the ram or automatically seizing the upper end of the broach when said n a broaching machine, two alined hyp I wenn@ broach has been raised by said plunger; and means for admitting oil to the upper cylinder to raise the ram when the breach has been gripped by said seizing means. Y 20. ln a hroaching machine, two alined hy- 5 draulic cylindersone above the other; a ram' reciprocable in the upper cylinder; a plunger reciprocable in the lower cylinder provided with a broach-receiving socket in its upper end; means for admitting oil to the lower cylinder beneath said plunger; `means on the lower endv of the ram for automatically seizing the upper end of the breach when the broach has been raised by said plunger; means for' admitting oil to the upper cylinder to raise the ram when the broach has been gripped by said seizing means; and automatic means for returning said ram to its lowest position. 20 Signed by me atv Ann Arbor, Michigan,

this ith day of ctober, 1927.

FRANCIS J. LAPOINTE. 

